This invention relates to a hunting arrowhead incorporating a removable cutting tip blade with individually removable ferrule blades having straight or concave cutting edges.
Hunting arrowheads or broadheads are well-known in the art. Prior art broadheads with multiple and replaceable blades typically include a ferrule body for receiving ferrule blades of various sizes and shapes, and nose tips of various configurations which are attached to the forwardmost end of the ferrule.
Most broadheads have two to six ferrule blades with razor-sharp outer edges configured in an axially diverging pattern. The ferrule blades are typically configured in such a way as to maximize kill-efficiency and aerodynamic stability. Generally, the larger the ferrule blade surface area, the more the arrow tends to veer due to sideways air friction. Therefore, broadheads having numerous ferrule blades, three or more, are less aerodynamically stable than broadheads with fewer blades or less ferrule blade surface area, and tend to veer from the target area. In an effort to minimize their tendency to veer, ferrule blades are often designed with cutouts or vents to minimize the planar surface area of each blade. Also, vented blades are lighter than ventless, solid blades and thereby have a lesser projectory drop-off than the ventless variety. While broadheads having less than three vented blades are truer in flight than broadheads having four or more ventless blades, there are certain advantages of the large-surface area broadheads. First, more blades attached to a broadhead can provide greater kill-efficiency due to increased cutting of tissue. Second, ventless blades are stronger and more durable if blade material is thick enough and do not break easily when striking hard objects such as bone, rock or trees.
The kill-efficiency of the arrow is also affected by the tip design of the broadhead. Kill-efficiency of an arrow is best measured by its penetrability. At present, there are three types of tip configurations. First, a tip of simple conical design, which allows for the least penetration of the three. Second, a tip of pyramid design which has three or four sides, has slightly better penetrability than the conical design. Third are unibody nonreplaceable ferrule blades which extend along the entire length of the ferrule at an axially converging angle to a sharp cutting tip, and allow for maximum penetration.
Although cutting tip designs have maximum penetration, they suffer from lack of durability when compared to the other types of tip designs. When a cutting tip hits a hard surface, the extreme tip is often broken or deformed such that the broadhead is no longer usable. Since blades are permanently attached to the body of the ferrule in the unibody broadheads, detaching and replacing the ferrule blades in these types of broadheads are not possible.